diff --git a/drivers/hwtracing/intel_th/acpi.c b/drivers/hwtracing/intel_th/acpi.c
index 87bc3744755f..b528e5b113ff 100644
--- a/drivers/hwtracing/intel_th/acpi.c
+++ b/drivers/hwtracing/intel_th/acpi.c
@@ -37,15 +37,23 @@ MODULE_DEVICE_TABLE(acpi, intel_th_acpi_ids);
 static int intel_th_acpi_probe(struct platform_device *pdev)
 {
 	struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
+	struct resource resource[TH_MMIO_END];
 	const struct acpi_device_id *id;
 	struct intel_th *th;
+	int i, r, irq = -1;
 
 	id = acpi_match_device(intel_th_acpi_ids, &pdev->dev);
 	if (!id)
 		return -ENODEV;
 
-	th = intel_th_alloc(&pdev->dev, (void *)id->driver_data,
-			    pdev->resource, pdev->num_resources, -1);
+	for (i = 0, r = 0; i < pdev->num_resources && r < TH_MMIO_END; i++)
+		if (pdev->resource[i].flags & IORESOURCE_IRQ)
+			irq = pdev->resource[i].start;
+		else if (pdev->resource[i].flags & IORESOURCE_MEM)
+			resource[r++] = pdev->resource[i];
+
+	th = intel_th_alloc(&pdev->dev, (void *)id->driver_data, resource, r,
+			    irq);
 	if (IS_ERR(th))
 		return PTR_ERR(th);
 
diff --git a/drivers/hwtracing/intel_th/core.c b/drivers/hwtracing/intel_th/core.c
index 7c1acc2f801c..c577b94ee606 100644
--- a/drivers/hwtracing/intel_th/core.c
+++ b/drivers/hwtracing/intel_th/core.c
@@ -491,7 +491,7 @@ static const struct intel_th_subdevice {
 				.flags	= IORESOURCE_MEM,
 			},
 			{
-				.start	= 1, /* use resource[1] */
+				.start	= TH_MMIO_SW,
 				.end	= 0,
 				.flags	= IORESOURCE_MEM,
 			},
@@ -584,7 +584,6 @@ intel_th_subdevice_alloc(struct intel_th *th,
 	struct intel_th_device *thdev;
 	struct resource res[3];
 	unsigned int req = 0;
-	bool is64bit = false;
 	int r, err;
 
 	thdev = intel_th_device_alloc(th, subdev->type, subdev->name,
@@ -594,18 +593,12 @@ intel_th_subdevice_alloc(struct intel_th *th,
 
 	thdev->drvdata = th->drvdata;
 
-	for (r = 0; r < th->num_resources; r++)
-		if (th->resource[r].flags & IORESOURCE_MEM_64) {
-			is64bit = true;
-			break;
-		}
-
 	memcpy(res, subdev->res,
 	       sizeof(struct resource) * subdev->nres);
 
 	for (r = 0; r < subdev->nres; r++) {
 		struct resource *devres = th->resource;
-		int bar = 0; /* cut subdevices' MMIO from resource[0] */
+		int bar = TH_MMIO_CONFIG;
 
 		/*
 		 * Take .end == 0 to mean 'take the whole bar',
@@ -614,8 +607,6 @@ intel_th_subdevice_alloc(struct intel_th *th,
 		 */
 		if (!res[r].end && res[r].flags == IORESOURCE_MEM) {
 			bar = res[r].start;
-			if (is64bit)
-				bar *= 2;
 			res[r].start = 0;
 			res[r].end = resource_size(&devres[bar]) - 1;
 		}
@@ -812,8 +803,7 @@ static const struct file_operations intel_th_output_fops = {
 /**
  * intel_th_alloc() - allocate a new Intel TH device and its subdevices
  * @dev:	parent device
- * @devres:	parent's resources
- * @ndevres:	number of resources
+ * @devres:	resources indexed by th_mmio_idx
  * @irq:	irq number
  */
 struct intel_th *
@@ -823,12 +813,8 @@ intel_th_alloc(struct device *dev, struct intel_th_drvdata *drvdata,
 	struct intel_th *th;
 	int err, r;
 
-	if (irq == -1)
-		for (r = 0; r < ndevres; r++)
-			if (devres[r].flags & IORESOURCE_IRQ) {
-				irq = devres[r].start;
-				break;
-			}
+	if (ndevres < TH_MMIO_END)
+		return ERR_PTR(-EINVAL);
 
 	th = kzalloc(sizeof(*th), GFP_KERNEL);
 	if (!th)
@@ -849,7 +835,8 @@ intel_th_alloc(struct device *dev, struct intel_th_drvdata *drvdata,
 	th->dev = dev;
 	th->drvdata = drvdata;
 
-	th->resource = devres;
+	for (r = 0; r < ndevres; r++)
+		th->resource[r] = devres[r];
 	th->num_resources = ndevres;
 	th->irq = irq;
 
diff --git a/drivers/hwtracing/intel_th/intel_th.h b/drivers/hwtracing/intel_th/intel_th.h
index 780206dc9012..8c90c8d01867 100644
--- a/drivers/hwtracing/intel_th/intel_th.h
+++ b/drivers/hwtracing/intel_th/intel_th.h
@@ -225,9 +225,9 @@ int intel_th_set_output(struct intel_th_device *thdev,
 			unsigned int master);
 int intel_th_output_enable(struct intel_th *th, unsigned int otype);
 
-enum {
+enum th_mmio_idx {
 	TH_MMIO_CONFIG = 0,
-	TH_MMIO_SW = 2,
+	TH_MMIO_SW = 1,
 	TH_MMIO_END,
 };
 
@@ -244,7 +244,7 @@ enum {
  * @hub:	"switch" subdevice (GTH)
  * @resource:	resources of the entire controller
  * @num_thdevs:	number of devices in the @thdev array
- * @num_resources:	number or resources in the @resource array
+ * @num_resources:	number of resources in the @resource array
  * @irq:	irq number
  * @id:		this Intel TH controller's device ID in the system
  * @major:	device node major for output devices
@@ -256,7 +256,7 @@ struct intel_th {
 	struct intel_th_device	*hub;
 	struct intel_th_drvdata	*drvdata;
 
-	struct resource		*resource;
+	struct resource		resource[TH_MMIO_END];
 	int			(*activate)(struct intel_th *);
 	void			(*deactivate)(struct intel_th *);
 	unsigned int		num_thdevs;
diff --git a/drivers/hwtracing/intel_th/pci.c b/drivers/hwtracing/intel_th/pci.c
index 1cf6290d6435..9dd2d75bd539 100644
--- a/drivers/hwtracing/intel_th/pci.c
+++ b/drivers/hwtracing/intel_th/pci.c
@@ -17,7 +17,12 @@
 
 #define DRIVER_NAME "intel_th_pci"
 
-#define BAR_MASK (BIT(TH_MMIO_CONFIG) | BIT(TH_MMIO_SW))
+enum {
+	TH_PCI_CONFIG_BAR	= 0,
+	TH_PCI_STH_SW_BAR	= 2,
+};
+
+#define BAR_MASK (BIT(TH_PCI_CONFIG_BAR) | BIT(TH_PCI_STH_SW_BAR))
 
 #define PCI_REG_NPKDSC	0x80
 #define NPKDSC_TSACT	BIT(5)
@@ -66,6 +71,10 @@ static int intel_th_pci_probe(struct pci_dev *pdev,
 			      const struct pci_device_id *id)
 {
 	struct intel_th_drvdata *drvdata = (void *)id->driver_data;
+	struct resource resource[TH_MMIO_END] = {
+		[TH_MMIO_CONFIG]	= pdev->resource[TH_PCI_CONFIG_BAR],
+		[TH_MMIO_SW]		= pdev->resource[TH_PCI_STH_SW_BAR],
+	};
 	struct intel_th *th;
 	int err;
 
@@ -77,8 +86,8 @@ static int intel_th_pci_probe(struct pci_dev *pdev,
 	if (err)
 		return err;
 
-	th = intel_th_alloc(&pdev->dev, drvdata, pdev->resource,
-			    DEVICE_COUNT_RESOURCE, pdev->irq);
+	th = intel_th_alloc(&pdev->dev, drvdata, resource, TH_MMIO_END,
+			    pdev->irq);
 	if (IS_ERR(th))
 		return PTR_ERR(th);